Apparatus and method for transporting and dispensing liquefied gas



INVENTOR. p5 TE/a PE FF BY 5,; WM 1 P. PEFF APPARATUS AND METHOD FDR TRANSPORTING AND DISPENSING LIQUIFIED GAS Filed March 5, 1949 April 22, 1952 Patented Apr. 22, 1952 APPARATUS AND METHOD FOR TRANS- PORTING AND DISPENSING LIQUEFIED GAS Peter Peff, Reno, Nev.

Application March 5, 1949, Serial No. 7 9,7 84

10 Claims. 1

This invention relates to apparatus for transporting and dispensing liquified gas, such, for example, as liquified oxygen, and has for one of its objects the provision of apparatus of said nature that is provided with means for controlling the pressure developed during transit, storage and dispensing more satisfactorily than heretofore.

Another object of the invention is the provision of relatively simple apparatus for transautomatically maintaining a desired gas pres- 7 sure within the container without objectionable loss of gas.

Other objects and advantages will be obvious -from the description and drawings.

The drawing is a semi-diagrammatic view of the apparatus.

In detail, the apparatus shown in the drawing comprises a main container or reservoir l, preferably of spherical shape, having an inner shell 2 adapted to receive and hold a charge 3 of liquified gas, such as liquid oxygen, with a space it above the level of the liquid, in which the gas of evaporation is held, and which gas provides for a gas pressure on the charge 3.

The shell 2 is enclosed by any suitable heat insulation material 5, and surrounding said material is an outer shell 6.

A passageway 1 extends laterally from the bottom of the inner shell, and communicates with an expansion chamber 8. Said passageway and chamber are also enclosed by heat insulation material 9 and an outer shell [0.

In communication with the expansion chamher 8 and adjacent the bottom thereof is a discharge valve Il enclosd by the heat insulation material 9. A discharge pipe [2 connects with valve H and extends outwardly through the insulation material 9 and outer shell l and through any suitable vaporizer I3 for vaporizing the liquid oxygen in said pipe.

any suitable connector [5 for connecting a conduit l6 therewith, and which conduit conducts the gas to any desired point.

A handle I! on valve ll provides means fo'r A continuation M of said discharge pipe may be provided with manually controlling the discharge of the oxygen or liquified gas to pipe l2 or for draining the liquid out of the storage container I.

The outer shell 6 of the container is provided with a conventional relief valve [8 for discharging any gas that may leak into the space containing the insulation material 5.

Opening into the upper end of the container l is a filling pipe provided with a removable cap 2| for filling the container to the desired level with liquid oxygen. A conventional safety valve 22 communicates with this pipe 20 through a pipe 23; and a pressure indicator or gauge 24 communicates with pipe 20 through a pipe 25.

Communicating with the space 4 in the upper end of the container I is a conduit 26 that may extend generally spirally around the inner shell 2 within the insulation material 5 and spaced between shells 2, 6.

The conduit 26 preferably commences at its upper end relatively close to the inner shell 2 and then is spaced progressively outwardly of shell 2 as it moves downwardly so that the lower end of the conduit where it emerges from the outer shell 6 is relatively close to the latter.

The said conduit 26 extends at its lower end at 21 from the container to the intake of any suitable compressor 28, the conventional check valve being in said intake.

A pipe 29 extends from the high pressure side of the compressor 28 through any suitable heat exchanger 30where the compressed gas :is cooled and from the heat exchanger the pipe 29 extends into the extension 21 of conduit 26 and through the latter into the container I where it passes downwardly through the liquid gas 3 to the bottom of the container and then through passageway 1 into chamber 8 where it, is provided with an expansion valve 3|.

Within the lower portion of container l', the pipe 29 is preferably formed with a coil 32 which coil may be of any desired number of turns.

The valve 3| is opened and closed by reciprocable movement of valve rod 33 that extends through a tube 34. The tube 34 extends through the insulation material 9 and shell 10 to outside the latter where a diaphragm housing may be secured thereto.

Diaphragm 35 divides the interior of the housing' into a pressure chamber 36 and a chamber 31, the latter containing the usual spring 38 that reacts against the diaphragm with a pressure determined by the manual adjusting screw 39.

Pipe 40 connects the pressure chamber 36 with the high pressure pipe 29 at the high pressure side of the compressor.

This valvecontrol is not new in itself, but in the present instance it provides one automatic control for the expansion valve 3|. As will be later described, valve 3| does not function to cause vaporization of the gas that reaches it in liquid form from pipe 29, but merely releases the liquid gas from a higher pressure than that under which the liquid 3 is held, and such release is into the liquid 3. The valve 3| can be adjusted to open at any desired pressure of the gas in chamber 36.

Also communicating with the gas in space 4 in container is a pipe 4|. This pipe 4| extends directly through the wall of container I and communicates at its opposite end with the high pressure pipe 29 extending from the high pressure side of the compressor before said pipe 29 enters conduit 21.

A conventional pressure control valve 42 is in the pipe 4| which valve is adapted to be controlled by the gas pressure in container I so as to open when the pressure in space 4 falls to a predetermined amount.

The valve 42 mayhave the usual Sylphon expansion chamber 43 associated therewith for longitudinal expansion upon increase of pressure therein and longitudinal contraction when the pressure drops. A valve rod connected with the movable end of the Sylp-hon will open the valve upon predetermined contraction of the sylphon, and will close the valve upon predetermined expansion. The structure employed is old in the art in itself, and no claim is made to the same apart from the combination.

The compressor 28 is actuated by any suitable power. An electric motor 45 is shown in the drawing, and preferably, this motor is controlled for actuation when the pressure of the gas in space 4 reaches a predetermined maximum and minimum, and is inoperative at any desired range of pressure between said maximum and minimum pressures.

The said control may be a pair of Sylphon chambers 45,-4.1, each having a corresponding end 48 secured stationary by any suitable means so that upon increase and decrease in the pressure Within the chambers the other head 49 of each Sylphon will move axially outwardly or inwardly relative to head 48. Obviously other arrangements may be made'to utilize the relative movement between heads 48, 49 but the present one is simple.

A pipe 55 communicates at one end with space 4 and at the opposite-end withthe Sylphon 43 of valve 42 while branches 52 respectively, communicate with the Sylphons 46, 41. Thus, Sylphons 43, 46, 4! are all directly responsive for movement to the pressure in space 4 uninfluenced by other pressures and Surges.

The head 49 of Sylphon 46 maybe connected by a rod 53 with a snap switch arm 54 actuated by a spring 55 when the arm is pulled over center by contraction of the Sylphon 45. Upon such movement of arm 54 the latter engages contact 55. Contact 55 is connected by wire 56 with a source of power 51, and arm 54 is connected by wire 58 with one of the terminals of motor 45. The other terminal of the motor is connected by wire 59 with said source of power. Hence when arm 54 engages contact 55 the motor is started and the compressor 28 is actuated.

The head of Sylphon 41 is connected by rod with the arm 6| of a snap switch. Spring 62 will cause the arm to quickly engage an electrical contact 53 when the said arm i pushed over center by the expansion of the Sylphon 41.

Arms 54, 5! are respectively pivoted at 54 to any suitable rigid support.

Contact 53 connects by wire 65 with wire 56 and the arm 5| connects by wire 55 with wire 58.

It is to be understood that the foregoing recitation of structural details is purely by way of example and is not to be considered restrictive. For example, the principal function of the switches actuated by the Sylphons is to cause actuation of the compressor when the gas pressure in container 2 reaches a predetermined maximum and minimum. Whether this control is by means of Sylphons or some other pressure actuatable device is not material, and a clutch between an engine and the compressor may be actuated by such pressure changes or the compressor can be actuated by any other suitable means, but such means should be preferably automatic.

The apparatus herein illustrated has been found to be suitable for delivery of liquid oxygen under pressures of say, somewhere between 50 lbs. per square inch and lbs. per square inch, as in large welding shops, shipyards, etc. The apparatus herein illustrated is preferably mounted on a trailer of vehicle (not shown) and may be left at the place of business of the user. The users pipe line I5 may be connected with the pipe line I2 and the apparatus will then be automatically actuated to maintain the pressur in line It at any pressure, up to, say 100 lbs. per square inch or at any pressure that the container I will stand.

In operation, after the container I is delivered full of liquid oxygen, and the filling tube 20 is closed by cap 2 I, any desired pressure can be built up within the container by regulating the evaporation of the liquid. The rate of evaporation may be increased by actuation of the compressor when valve 42 is open and the expansion valve 3| is closed. The gas in space 4 will be drawn through conduit 25 into the compressor and will be pumped in a warm condition back into the container through valve 42 and pip 4|. This warm gas will increase the rate of evaporation of the liquid 3 and will result in an increase in the pressure in space 4 to the desired degree, which may be any predetermined pressure, and at which pressure the valve42 will preferably close automatically by reason of the pressure in Sylphon 43.

In the event of a drop in the pressure to a predetermined degree, the operation will be repeated, but the chances of there being such drop are small, unless the liquid oxygen is withdrawn at a rapid rate. Otherwise, the tendency will be for the pressure in the space 4 to increase all the time due to heat losses through the insulation.

When and if the pressure inside the container i should reach a predetermined maximum pressure, of say 100 lbs. per square inch, for example, and it becomes necessary to reduce such pressure, the valve 42 will be closed atsuch pressure, but the valve 3| will be opened and the compressor will be started by closing ofthe switch 5| due to expansionof Sylphon 41. Obviously the valve 3| may be opened manually if desired, as indicated in my co-pending applicationserial No, 68,903, filed January 3, 1949, but this action is preferably automatic.

This operation will result in withdrawal of the gas through conduit 26 and sub-cooling of the liquid oxygen 3 by reason of liquification oi the compressed gas in pipe 29 and coil 32 and the release of such liquified gas into the liquid gas 3 at a pressure substantially above that of the liquid 3, as more fully described in the above mentioned application.

The actuation of the compressor upon a drop in the pressure in space 4 to any predetermined minimum, say 50 lbs. per square inch. will result in actuation of the compressor by closing the circuit through switch 54 and opening of valve 42 so that the pressure will be built up to the desired point of say, 80 or 90 lbs. per square inch. Inasmuch as the switches 54, 6| will not be actuated until after a predetermined expansion or contraction of the bellows, it will be seen that the compressor will continue operating until the desired pressure is reached.

The Sylphon 43 may be adjusted to open when the pressure falls below the desired pressure in the container I and will close when the switch 54 is opened and the compressor stops.

By the foregoing system there is a double automatic control of the pressure by reason of the actuation of the compressor when the pressure reaches a maximum and a minimum without discharging the gas. The lowering of the pressure by liquification of oxygen in space 4 occurs through sub-cooling and releasing the gas so liquified back into the body of the liquid, while the elevating of the pressure is through increasing the rate of evaporation of the liquid by withdrawing the vaporized gas from space 4 and blow ing it back into said space in a warm condition.

It is obvious that in some instances the expansion valve may be directly in the body of liquid in container I and the discharge valve I! may be at the bottom of said container. Also pipe 29 need not necessarily extend through conduit 26, although such arrangement simplified the structure and results in a heat exchange between the gas drawn outwardly through conduit 26 and the warmer gas in pipe 29 where the pipe passes through the conduit. When the gas in pipe 29 reaches the expansion valve it is liquified, and is under considerably higher pressure than the liquified oxygen.

I claim:

1. An apparatus for transporting and for dispensing liquified gas having a boiling point below 273 K., having a thermally insulated container for holding a charge of said gas below its boiling temperature under the pressure of such gasin the gaseous phase in a space over said charge, a compressor having its intake and its outlet in communication with said space for withdrawing said gas therefrom and injecting the same back into said space at a higher temperature resulting from its compression to thereby accelerate evap-' oration of the liquified gas in said container, means for closing communication between said outlet and said space and a pipe extending from said outlet into direct heat transfer relationship with the liquified gas in said container for lowering the temperature of gas in said pipe to that of the said liquified gas, a valve in said pipe and within said liquified gas for releasing the liquified gas from said pipe into the body within said container, an element responsive to the pressure within said space for movement in one direction upon a predetermined increase in pressure within said space and for movement in the opposite direction upon predetermined decrease in said pressure, said means being a valve, and said element being connected with said last mentioned valve for opening the latter upon said predetermined decrease, and for closing said valve upon said predetermined increase.

2. An apparatus for transporting and for dispensing liquified gas having a boiling point below 273 K., having a thermally insulated container for holding a charge of said gas below its boiling temperature under the pressure of such gas in the gaseous phase in a space over said charge, a compressor having its intake and its outlet in communication with said space for withdrawing said gas therefrom and injecting the same back into said space at a higher temperature resulting from its compression to thereby accelerate evaporation of the liquified gas in said container, means for closing communication between said outlet and said space and a pipe extending from said outlet into direct heat transfer relationship with the liquified gas in said container for lowering the temperature of gas in said' pipe to that of the said liquified gas, a valve in said pipe and within said liquified gas for releasing the liquified gas from said pipe into the body within said container, a member responsive to the pressure within said space when said means is open for movement in one direction upon increase in pressure within said space and for movement in the opposite direction upon a decrease in said pressure, said member being connected with said valve for opening the latter upon such increase in pressure to a predetermined degree and for closing said valve upon decrease in said pressure to a predetermined degree, second pressure responsive means in communication with the gas in said space responsive to the pressure within said space for movement in one direction upon elevation of said pressure to a predetermined amount for movement in the opposite direction upon a predetermined reduction in said second pressure, power means for actuating said compressor, means connecting said pressure responsive means with said power means for causing actuation of the said compressor upon said predetermined elevation and upon said predeter mined reduction, said second pressure responsive means being inoperative for causing said actuation of said compressor at a predetermined pressure between said predetermined elevation and said predetermined reduction.

3. An apparatus for transporting and for dispensing liquified gas having a boiling point below 273 K., having a thermally insulated container for holding a charge of said gas below its boiling temperature under the pressure of such gas in the gaseous phase in a space over said charge, a compressor having its intake and its outlet in communication with said space for withdrawing said gas therefrom and injecting the same back into said space at a higher temperature resulting from its compression to thereby accelerate evaporation of the liquified gas in said container, means for closing communication between said outlet and said space and a pipe extending from said outlet into direct heat transfer relationship with the liquified gas in said container for lowering the temperature of gas in said pipe to that of the said liquified gas, a valve in said pipe and within said liquified gas for releasing the liquified gas from said pipe into the body within said container, a member responsive to the pressure within said space when said means is open for movement in one direction upon increase in pressure within said space and for movement in the opposite direction upon a decrease in said pressure, said member being connected with said Valve for opening the latter upon such increase 'in pressure to a predetermined degree and for closing said valve upon decrease in said pressure to a predetermined degree, second. pressure rsponsive means in communication with the gas in said space responsive to the pressure within said space for movement in one direction upon ing actuation of the said compressor upon said predetermined elevation and upon said predetermined reduction, said second pressure responsive means being inoperative for causing said actuation of said compressor at a predetermined pressure between said predetermined elevation and said predetermined reduction, an element responsive to the pressure within said space for movement in one direction upon a rise in the pressure within said space to a predetermined degree and for movement in the opposite direction upon a lowering of said pressure to a predetermined degree, saidfirst mentioned means being a last mentioned valve, and said element being connected with said valve for opening the latter upon said predetermined lowering and for closing said valve upon said predetermined rise, said predetermined increase, elevation and rise being substantially the same pressure, and said predetermined decrease, lowering and reduction being substantially the same pressure.

4. The method of controlling the gas pressure on an enclosed body of liquii'ied gas having a boiling temperature below 273 KI, that comprises the steps of providing a space over said body and within the enclosure there-for for the gas of evaporation of said liquified gas, accelerating the rate of evaporation of said liquified gas upon the pressure within said space decreasing to a predetermined degree by withdrawing gas of evaporation from said space then injecting the same back into said space and into heat transfer relation with said body at a higher temperature than its temperature before said withdrawal, reducing the pressure within said space upon a rise in the pressure therein to a predetermined point substantially above said predetermined degree by withdrawing gas of evoporation from space, then liquifying the same by reducing it to the temperature of said liquified gas and injecting the gas so liquified back into said body at a pressure above the pressure in said space.

5. The method of controiling the gas pressure on an enclosed body of liquified gas having a boiling temperature below 273 K., that comprises the steps of providing a space over said body and within the enclosure therefor for the gas of evaporation of said liquified gas, accelerating the rate of evaporation of said liquified gas upon the pressure within said space decreasing to a predetermined degree by withdrawing gas of evaporation from said spac then injecting the same back into said space and into heat transfer relation with said body at a higher temperature than its temperature before said Withdrawal, reducing the pressure Within said space upon a rise in the pressure therein to a predetermined point substantially above said predetermined degree by withdrawing gas of evaporation from said space, then liquifying the same by reducing it to the temperature of said liquified gas and injecting the gas so liquified back into said 8 body" at a pressure above the pressure in said space, utilizing th pressure of said gas in said space for causing said withdrawal of said gas therefrom and the reinjecting thereof back into said space and body respectively in said gaseous phase and in said liquified phase.

6. Apparatus for transporting and dispensing liquified gas having a boiling point temperature below 2'73 K, which comprises a thermally insulated container for holding a charge of said gas below its boiling point temperature under the pressure of such gas in said container in the gaseous phase, means for withdrawing gas in said gaseous phase from said container and for compressing to an elevated pressure above that of the pressure in said container, a pipe connected with said means extending into said'container and into said charge in direct heat transfer relationship to the latter for conducting the gas from said means into said charge for liquifying said gas at said elevated pressure, an expansion valve in said pipe submerged in said charge for releasing the liquified gas in said pipe into said charge and container, a pressure controlled element movable for opening and closing said valve, said element being in communication with the gas in gaseous phase in said container for actuation thereof by the pressure of said gas for opening said valve upon apredetermined increase in the pressure of said gas and for closing said valve upon a predetermined decrease in said latter pressure.

'1. Apparatus for transporting and dispensing liquified gas having a boiling point temperature below 273 K, which comprises a thermally insulated container for holding a charge of said gas below its boiling point temperature under the pressure of such gas in said container in the gaseous phase, means for withdrawing gas in said gaseous phase from said container and for compressing to an elevated pressure above that of the pressure in said container, a pipe connected with said means extending into said container and into said charge in direct heat transfer rela tionship to the latter for conducting the gas from said means into said charge for liquifying said gas at said elevated pressure, an expansion valve in said pipe submerged in said charge for releasing the iiquified gas in said pipe into said charge and container, a pressure controlled element movable for opening and closing said valve, said element bein in communication with the gas in gaseous phase in said container for actuation thereof by the pressure of said gas for opening said valve upon a predetermined increase in the pressure of said gas and for closing said valve upon a predetermined decrease in said latter pressure, said means including a compressor and a motor connected therewith for actuation thereof, means in communication with the gas in said container in said gaseous phase responsive for movement under the influence of the pressure of said gas for causing actuation of said motor upon a predetermined increase in the pressure of said gas and for discontinuing the actuation of said motor upon a predetermined drop in said pressures.

8., Apparatus for transporting and dispensing liquified gas having a boiling point temperature below 273 K. which comprises a thermally insulated container for holding a charge of said gas below its boiling point temperature under the; pressure of such gas in said container in the gaseous phase, means for withdrawing gas in said gaseous. phase from said container and. for compressing to an elevated pressure above that of the pressure in said container, a pipe connected with said means extending into said container and into said charge in direct heat transfer relationship to the latter for conducting the gas from said means into said charge for liquifying said gas at said elevated pressure, an expansion valve in said pipe submerged in said charge for releasing the liquified gas in said pipe into said charge and container, a pressure controlled element movable for opening and closing said valve, said element being in communication with the gas in gaseous phase in said container for actuation thereof by the pressure of said gas for opening said valve upon a predetermined increase in the pressure of said gas and for closing said valve upon a predetermined decrease in said latter pressure, a discharge pipe extending from said charge to outside said container for discharge of liquid gas from said container under the pressure of the gas in said gaseous phase.

9. Apparatus for transporting and dispensing liquified gas having a boiling point temperature below 273 32., which comprises a thermally insulated container for holding a charge of said gas below its boiling point temperature under pressure of such gas in said container in the gaseous phase, means for withdrawing gas in said gaseous phase from said container and for compressing to an elevated pressure above that of the pressure in said container, a pipe connected with said means extending into said container and into said charge in direct heat transfer relationship to the latter for conducting the gas from said means into said charge for liquifying said gas at said elevated pressure, an expansion valve in said pipe submerged in said charge for releasing the liquifled gas in said pipe into said charge and container, a pressure controlled element movable for opening and closing said valve, said element being in communication with the gas in gaseous phase in said container for actuation thereof by the pressure of said gas for opening said valve upon a predetermined increase in the pressure of said gas and for closing said valve upon a predetermined decrease in said latter pressure, a discharge pipe extending from said charge to outside said container for discharge of liquid gas from said container under the pressure of the gas in said gaseous phase, a valve enclosed within the 10 heat insulation of said container and in said discharge pipe for opening and closing said latter pipe.

10. Apparatus for transporting and dispensing liquified gas having a boiling point temperature below 273 K., which comprises a thermally insulated container for holding a charge of said gas below its boiling point temperature under the pressure of such gas in said container in the gaseous phase, means for withdrawing gas in said gaseous phase from said container and for compressing to an elevated pressure above that of the pressure in said container, a pipe connected with said means extending into said container and into said charge in direct heat transfer relationship to the latter for conducting the gas from said means into said charge for liquifying said gas at said elevated pressure, an expansion valve in said pipe submerged in said charge for releasing the liquified gas in said pipe into said charge and container, a pressure controlled element movable for opening and closing said valve, said element being in communication with the gas in gaseous phase in said container for actuation thereof by the pressure of said gas for opening said valve upon a predetermined increase in the pressure of said gas and for closing said valve upon a predetermined decrease in said latter pressure, said pipe including a coiled length thereof submerged within said charge.

PETER PEFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,371,427 Kerr Mar. 15, 1921 1,427,112 Lissaver Aug. 29, 1922 1,905,971 Davisson et al Apr. 25, 1933 2,004,074 Kiley June 4, 1935 2,033,094 DeMotte Mar. 3, 1936 2,059,942 Gibson Nov. 3, 1936 2,451,151 Byram Oct. 12, 1948 2,510,140 Rausch June 6, 1950 FOREIGN PATENTS Number Country Date 8,661 Australia 1932 

